The birth of the royal baby will have a limited yet "overwhelmingly positive" effect on UK growth, according to Howard Archer, chief UK economist at IHS Global Insight.

"At the margin, the royal birth may provide the economy with a temporary, small positive boost at a time when it seems to be increasingly moving in the right direction," he said.

The most obvious support to growth will come via a pick-up in retail sales as people buy souvenirs and commemorative merchandise, as well as alcohol to toast the birth, he said. Mr Archer also noted the lift bookies have already experienced as punters bet on the baby's sex and name.

More broadly, Mr Archer said a "feel good factor" around the birth could translate into a fleeting improvement in consumer confidence, which would come with "no obvious negative economic repercussions".

That contrasts with the Royal Wedding in 2011, when an extra day's public holiday to mark the occasion impacted the UK's economic output as workers downed tools. However, the festivities did appear to help retailers, as indexes tracking consumer confidence showed sentiment enjoyed a leap.

Victoria Clarke, an economist at Investec, cautioned however that such surges in consumer sentiment tend to be short-lived, evaporating in the following month’s data. “Beyond the impact of memorabilia sales... you are then down to confidence and whether it lasts,” she said.

Mr Archer, too, acknowledged the limitations of the baby's ability to transform Britain's economic fortunes. "At the end of the day what influences people the most is their perception of the state of the economy and the employment outlook," he said.